If your trackball becomes inoperative you may have to replace it. In order to change the TB on the Bold, you must preform surgery. You must take the entire device apart to get to it. It's rather easy as long as you take your time. All you need is a T5 Torx drive. Check Sears or your local hardware store. You can find a disassembly video at the link below. Just be sure to take your time.-->